fix: use v1 sources format instead of deprecated http_sources for URL conversion

The /v1/convert/source endpoint requires the new discriminated union format
with "sources": [{"kind": "http", "url": ...}] instead of the deprecated
"http_sources" field. Updated both sync and async code paths and tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: cbrumm

integrations/docling_serve/src/haystack_integrations/components/converters/docling_serve/converter.py

@@ -182,7 +182,7 @@ def _convert_url_sync(
         url = f"{self.base_url}{_SOURCE_CONVERT_PATH}"
         payload: dict[str, Any] = {
             "options": self.convert_options,
-            "http_sources": [{"url": source_url}],
+            "sources": [{"kind": "http", "url": source_url}],
         }
 
         with httpx.Client(timeout=self.timeout) as client:
@@ -218,7 +218,7 @@ async def _convert_url_async(
         url = f"{self.base_url}{_SOURCE_CONVERT_PATH}"
         payload: dict[str, Any] = {
             "options": self.convert_options,
-            "http_sources": [{"url": source_url}],
+            "sources": [{"kind": "http", "url": source_url}],
         }
 
         async with httpx.AsyncClient(timeout=self.timeout) as client:

integrations/docling_serve/tests/test_converter.py

@@ -202,7 +202,7 @@ def test_converts_url(self):
         call_kwargs = mock_post.call_args
         assert "/v1/convert/source" in call_kwargs.args[0]
         body = call_kwargs.kwargs["json"]
-        assert body["http_sources"] == [{"url": url}]
+        assert body["sources"] == [{"kind": "http", "url": url}]
 
     def test_http_url_detected(self):
         converter = DoclingServeConverter(api_key=None)